278 



BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



The reefs of the St. Martin Plateau are superposed on an ante- 

 cedent platform that was brought into its present relations to sea 

 level by geologically Recent submergence to an amount of about 20 

 fathoms. 



65° 



18 



115/ -.it 

 pollers freqacnlhj occur / 

 from October to May / 



HO,— 

 -—''30 35 33 

 'il 



8 19 



UO 



ao 17 



19 21 ^> 

 13 ■ — 



s; 







4 „ f..9.%! 



11 13 IS f^ S * 'lo .•' V/ 



18^^^ 25 9^-^18 ;Vl4^ .... «=12^^ 



13 ?CJl# ..'13 4^ 



'126 



i 13<?V S"® if^^r'A ** 937 



^ 13 /; 1.16 / V 







861 ^ 



980 



2j_ -' ,-_ 20 

 '2:58\lT/!.'88 -- 



15;-'- 336 



_^' 350 \ 



SSO 



isso X- 



V 1355 



^ 



G 



V 



1061 



875 



"^ 1350 



1116 519 



900 



695 



1091 

 861 



2il2 

 2376 



1630 990 



16T0 



550 



910 

 5G0 

 313 



1951 

 4i0 



325 



1253 



fl.5S ^ 219_ii'i-^ 551 



1600 r-on 131-(£ l?3--'--^:^^-'^'^'a2^3;i80 



. If* '*'.,, q /;&•-. r ^-^'13 15, ICV 



sT.cRoS^p i ■■'- ■ : ■ :^^ 3p!^>#^'« 



T58 765 862 



879 



.355 



■ -fi' 16, L-'' 315 



679 



,^-—--'105 



18 



65 



Fig. 13.— Chart of virgin islands and st. ceoix. Fkom U. S. HTDEOGEAtnic chart no. 2318. Scalk, 



ONE mCH=^ABOUT 12.8 NAUTICAL MILES. 



ST. CROIX ISLAND. 



This island rises above a bank about 30 miles long and 10 miles 

 wide. The distance from the shore to the 100-f athom curve is usually 



